To Fix The Wizarding World
by ShotgunLagoon
Summary: A mysterious woman appears in the middle of the Great Hall during the Halloween Feast in a cloud of smoke and proceeds to turn the Wizarding World upside down. Gen. This is my first published fic, so, please tell me what you think. Before "OC" scares you off, it's not a self insert or a Mary Sue (as far as I can tell).
1. Chapter 1

It was Halloween. The Great Hall was filled with hyper students eating candy, laughing, and celebrating. The Golden Trio were conspicuously absent, but most ignored this and assumed they were off on some other Great Adventure, like the mysterious events of the previous year surrounding the forbidden 3rd floor corridor, or the unusual method of arrival of Harry Potter and Ronald Weasley that year itself, involving, if rumors were to be believed, a flying car of all things crashing into the castle that came to life and went to go live with the centaurs in the Forbidden Forest.

As the feast was winding up, a loud bang echoed through the hall. A bright pinprick of light blinked into existence in the middle of the hall and quickly blossomed into an almost perfect hemisphere of thick black smoke that shimmered eye-catchingly. Everyone's attention was fully on the smoke when a faint shadow appeared within it, shaped like a person on their knees. A loud, raspy coughing started to come from the smoke, and eyes followed the figure as it crawled to the edges of the smoke and collapsed, body shaking violently with coughs. More than a few people wondered if they were about to see someone literally cough up a lung. The figure stilled, and as the smoke began to clear, the students noticed it was a fairly short young woman wearing dark robes, with long black hair that was spread in a giant tangle around her, looking rather as if it had been electrocuted and then experienced a small but very energetic tornado. As the teachers finally got over the shock of seeing someone appear in the middle of the Great Hall in a ball of smoke, Headmaster Dumbledore and Professor Snape came down to stand in front of her, wands at the ready. Hagrid hurried off the to hospital wing to go fetch Madam Pomfrey at the muttered request of Professor McGonagall.

The school watched with bated breath for the woman to move. It still surprised them, however, and many jumped in their seats as a low groan issued from her.

"Merlin, I am so screwed," she said. Her voice was rather low for a woman, but still too high to be mistaken for anything but female. It was rather hoarse, presumably from the coughing, and cracked a bit at the end of her sentence. The pushed herself up onto an elbow and tried to use the other hand to push her mass of hair out of her face, but failed when she tried to pull out hair from under her elbow and collapsed back into her face. Another low groan, this one a bit louder was heard, muffled by the thick hair and the ground. A couple of people giggled a bit nervously, as if they weren't sure whether or not to laugh.

Headmaster Dumbledore cautiously asked, "Ma'am? Are you… well? Do you require any assistance?"

"A hand in getting up would be appreciated. And maybe get a picture of the runic circle before it disappears," she said in a light tone, as if this were an everyday occurrence. "I'd like to be able to figure out what I just did so I can fix it," she muttered, stretching a hand up and lifting her head towards the two professors, peering at them through her hair.

Professor Snape looked behind her to see that there was in fact a circle of runes on the ground, glowing faintly. They were in a disturbingly familiar shade of rusty red, and he could only hope that his suspicions were incorrect. The Headmaster moved to put the runes under a statis charm until they could be copied down onto parchment while Professor Snape pulled the young woman to her feet, keeping his other hand on his wand.

"Thank you. Right then, where am I? Ah, Great Hall. Hogwarts. Halloween? Strange, it was… March? April? Hm, guess I lost track. Either way, some time travel, some spatial travel at the very least," the woman muttered under her breath looking around with a critical eye. She scanned the students, eyes catching on a couple. "Where is everybody? At least a quarter of the students are missing, and Halloween Feast is usually everybody." She turned her scrutiny towards the High Table as Professor Snape watched her warily.

"Is everything alright Ms…," he asked leadingly.

"Hm? Oh, Professor actually. Professor Clay. No, nothing is alright," she said distractedly, pulling her eyes away from the High Table with effort. As she focused her attention on Snape, her eyes narrowed. "Severus?" she asked in a surprised voice. "Is that you?"

"That is my name, although I do not seem to recall giving you permission to use it. And how are you a professor?" he said, gripping his wand tighter.

"What in Merlin's name happened to you? You're so… pale! And thin! And all this black!" she exclaimed, pulling on the robes as if to get a closer look.

A couple students started to giggle, then suddenly started coughing as Professor Snape glared at them. "Excuse me?" he growled, offended, snatching his robes back.

"And the teachers? Albus, what are you even doing here? You rarely visit Hogwarts these days. And why is that fraud Lockhart sitting with the other professors?"

Headmaster Dumbledore's eyes twinkled at the Professor Clay. "I believe I have figured it out! Do take a look at your runic circle Ms. Clay."

The school watched in confusion as the woman knelt down and began to study the runes that had brought her there. Her face rapidly paled as her eyes widened in fear and horror.

"Oh no. Oh no. No no no. Nonononono! This can't be!" she choked out.

"What is it?" Professor Snape snapped irritably.

Clay turned her fear-filled eyes on him, and he barely had a second to notice their teariness before she said, "I just erased myself from history."


	2. Chapter 2

AN: Well! People are actually reading this! I am just a teensy bit terrified. Ok, very terrified.

FYI, I don't actually know exactly where this is going, so... yeah.

I love to see reviews! Even if they're only like 5 words long. So leave a review, tell me you like it!

If you guys have any ideas on how to make this better or if I made a typo or something, let me know so I can fix it. I don't proofread anything at all and I don't have a beta, so some things may slip through.

Enjoy!

* * *

"You… erased yourself from history? What does that even mean?" a curious and eacger voice called from the Ravenclaw table.

"I… I don't know!" Clay ran a hand through her already messy hair. "I… I'd done some of the disappearance runes…um... some of the… the runes that determine arrival location… and some of the temporal ones, but that's when the circle activated. I was… I was trying to fix Apparition! _This_ was not supposed to happen!" she babbled, growing agitated.

That was when Hagrid returned with Madam Pomfrey. She took one look at Clay and immediately ordered everyone to step away.

"Severus, a Calming Draught if you please?"

Professor Snape silently handed a vial over.

"Drink this," she commanded, pressing the vial into Clay's hands. Clay stared at it bewilderedly, eyes already red and puffy from the silent tears streaming down her face. "It's just a Calming Draught, drink it," Madam Pomfrey repeated slowly, opening the vial and pushing the hand holding it up towards Clay's mouth.

Clay downed the Draught in one swallow suddenly, making a couple people jump.

"How did she get into this state?" Madam Pomfrey demanded rounding on Professor Snape. "She's hysterical!"

A floaty voice behind her answered, "Oh, I just erased myself from history and had a breakdown. Lost my entire life in a couple minutes, you know. It's rather taxing to come to terms with something like that. All of it, poof! No more. Kiri's gone, Dev's gone, Jules probably has no idea who I am if he even exists, I've lost my job, my family, my money, my home, all my research, everything. It's… overwhelming. I apologize for my lapse of control, though." Clay lay down on the ground, yawning widely and bundling her hair underneath her like a pillow, then promptly passed out from emotional exhaustion.

No one spoke for a moment, trying to wrap their heads around the idea. The few who managed turned very pale and resolved to never think about it again for fear of destroying their sanity. Dumbledore looked contemplative, and Madam Pomfrey was blinking away the tears in her eyes rapidly.

"Well! That would do it. Best get you into the hospital wing before you catch a cold," she said briskly, voice wavering. "_Mobilicorpus_!"

As soon as Madam Pomfrey had left, the Great Hall broke into whispers and murmurs, students gossipping and speculating.

"...erased from history!"

"...those names…"

"Did you hear what she said to Snape?"

"... professor of what?"

"... _fixing_ Apparition…"

"... runes can do that?"

"... his robes… "

"... called him _Severus_!"

"I should copy down those runes…"

"... Professor Clay…"

As the feast came to a close, the students filed out of the Great Hall heading towards their dorms to sleep, but it wasn't to be. The students rounded a corner, when they saw it.

In front of the abandoned girls' bathroom on the first floor stood the Golden Trio, staring at a bright red message written in dripping letters.

_The Chamber of Secrets has been opened. Enemies of the Heir, beware._

The Hogwarts rumor mill wouldn't be getting a break anytime soon.

Draco Malfoy spotted Mrs. Norris hanging from a torch. He sneered gleefully, "You'll be next, Mudbloods!" A couple people gasped and Professor McGonagall snapped, "10 points from Slytherin for language!"

Filch saw Mrs. Norris and immediately began looking for someone to blame. His eyes fell on the Golden Trio and narrowed hatefully. "You three were here first! No one ever liked sweet Mrs. Norris and you killed her! You killed poor Mrs. Norris! Murderers! _Murderers!_" he accused, spitting in anger.

"Now now, Argus, you can't accuse students of murder like that!"

"She's not dead," called Headmaster Dumbledore from next to Mrs. Norris. He waved his wand over her. "Merely petrified, Argus."

Filch rushed over and untied Mrs. Norris from the wall sconce and gently stroked her fur, murmuring comforts. A couple students recoiled at the sight as Filch's face wasn't made for gentle expressions and looked rather terrifying.

"Students, return to your dorms. Curfew is soon. The professors will investigate this message on the wall and revive Mrs. Norris as soon as possible," Headmaster Dumbledore announced. The Heads of Houses herded their students to bed and came back to the corridor when they were done.

"Halloween's have become rather exciting recently, haven't they?" Dumbledore said, twinkling.

Professor Snape raised an eyebrow, unimpressed.

"Yes, yes, but what are we going to do? The Chamber of Secrets, again? Don't you remember, Albus? The last time this happened, a girl died! This is a serious matter!" Professor McGonagall said crossly. "I don't know how you can take this so lightly."

"And there's that poor dear, Clay, as well. Could she have anything to do with this?" Professor Sprout added, worriedly twisting her hat in her hands.

"No, she appeared during the feast and she's been with Poopy since then, unconscious!" Professor Flitwick reasoned. "Unless something connects them, we must assume the two are unrelated. Besides, I doubt Clay is the Heir. She seemed a bit too…"

"Crazy?" Professor Snape offered dryly. Professor Flitwick frowned, then nodded.

"Ah yes, Ms. Clay. She is a mystery. By definition, no one knows anything about her as she's apparently erased herself from history! We need to question her," Headmaster Dumbledore interjected.

"Do wait until the morning though, Albus. The poor girl's had a horrible experience. Do let her sleep," Professor Sprout requested.

"Of course, of course...," he trailed off. "Well, I suppose right now we ought to get to bed ourselves. Nothing to be done at the moment. May as well be well-rested! It's going to be _very_ busy tomorrow. Chamber of Secrets, indeed! I can only wonder what explanations the students will have come up with by morning. Good night, Pomona, Filius, Minerva, Severus. Sleep well." He nodded at each of them in turn, then turned to go down the corridor, humming a cheery tune. The Heads of Houses watched him go, made their goodbyes, then split apart to head to their quarters.


	3. Chapter 3

Clay opened her eyes to a high white ceiling. She sat up in bed to look around and recognized the hospital wing.

'What am I doing in the hospital wing? I don't recall getting hurt...

'Let's see, woke up, listened to Jules rant about paperwork, breakfast, finished my calculations... tested them... Oh Merlin, I hope that was all just a really lame dream!'

She pushed off the bed, triggering a ward that alerted Madam Pomfrey.

"Oh no, dear, you have to wait here. The Headmaster needs to speak with you!"

"Don't you mean Headmistress?" Clay asked with a sinking feeling.

Madam Pomfrey looked at her strangely. "No... Unless Dumbledore has something he's been hiding from us."

"Oh, I was hoping it had all been a dream. Minerva was Headmistress in my... time? universe? reality? You know what I mean."

Madam Pomfrey smiled sympathetically. "I'm sorry dear, I'm afraid it wasn't a dream."

They fell silent.

"By the way, you never did properly introduce yourself."

"I didn't exactly realize you didn't know who I was. I'm rather well known in my... Whatever. Cassiopeia Clay. Call me Cassie."

"Nice to meet you, I'm Poppy Pomfrey."

Cassie smiled wryly. "I know. I used to teach here."

That was when Dumbledore strode in. "Good morning! I trust you slept well?"

"I was fine until I woke up," Cassie said with a sad smile. "Then I remembered… well, you know."

"Ah, yes, well–"

"Madam Pomfrey said you had some questions for me?" she interrupted.

"Yes, I did. I don't believe we've been properly introduced. Albus Wulfric—"

"I actually do know you who are, as you happened it exist back in my reality. I'm Cassiopeia Antares Clay, _please_ just call me Cassie. That's probably not very helpful though."

"No, not particularly," Dumbledore chuckled. "Perhaps a more general introduction? What you do, where you went to school, your favorite color, that sort of thing?"

Cassie huffed a laugh. "Well, I'm actually a professor at Hogwarts. I teach—well, taught—Potions and Defensive Magic. I am—no, was—also Deputy Headmistress. Let's see, I went to Hogwarts myself, I got Masteries in Defense and Potions after I graduated, and I was working on a Dual Mastery in Runes and Arithmancy when this entire… _thing_… happened. I… like… navy blue. Hmm, what else?" she wondered aloud.

Dumbledore was a bit confused about teaching two subjects, but filed the information away to ask about later. "You mentioned a couple names last night, Jules, I think, was one of them. Who are they?"

"Jules is my brother. Kiri is my owl, Dev is sort of… an assistant, I suppose," she answered absentmindedly. "Actually, I have a small favor to ask."

"Yes?" Dumbledore asked curiously.

Cassie smiled hopefully. "Would it be terribly difficult to bring me a couple books on modern magical history? Preferably not anything about goblin rebellions, Binns was enough for me. Wizarding history, maybe for the last century or so?"

"The last century? Surely nothing before your birth could be changed. Wouldn't the last 30 years or so be more useful?"

Cassie bit her lip nervously, offering, "I'm older than I look?"

Dumbledore frowned, questioning, "Exactly how much older?"

She frowned in concentration. "What year is it right now?"

"1992, although that would hardly make a difference in your age. It's the year that you left that matters, isn't it?"

"Of course, just checking!" she assured, smiling innocently. "Can't we just say older than I appear and leave it at that? Please, I really could use those books. It's important that I understand recent events in history, particularly to compare them to my… reality."

"Of course, of course, I will get you your books," said Dumbledore graciously. "Although I do have a couple more questions to ask."

"Go ahead," Cassie said, waving him on.

"What particular major changes do you believe you might have made?"

"Ah. Well. I can't really answer that unless I know what this... reality is like, now can I?"

"Speculation is fine, of course."

Cassie leaned back against the bed frame, head tilted towards the ceiling in thought. "Hmm… Jules is probably completely different. Maybe he never even became Minister. In fact, his name's probably not even Jules." She looked a bit queasy, and suddenly changed the topic, "I know for a fact that there are a _lot_ less students than I remember and it worries me to think what may have caused that." At that, she looked pointedly at Dumbledore, but he remained silent. "I suppose all the magical advancements I made personally never came into existence. Severus looked horrible, I mean that in the best way possible, of course, but I can't figure out how my not existing could have done that… no, wait, scratch that, sudden epiphany."

"Would you like to share?" Dumbledore asked, raising an eyebrow.

Cassie grimaced apologetically. "Sorry, it's a bit personal. I don't think he'd appreciate me revealing his personal secrets to anyone."

"Please,then, by all means, continue."

Cassie sighed. "I'm sorry, Albus, but there isn't really much else I can think of. I don't know. _You're_ still Headmaster, instead of Minerva, so there's another change. I guess Kiri the First probably died. Dev never existed. Honestly, I have no idea. I have no idea how different this world is. Expecting a huge change would be rather egoistic of me, but expecting no change at all is clearly incorrect as apparently, nothing seems to be the same!" By this point, she was shouting in frustration. She caught herself, took a couple deep breaths, then closed her eyes and leaned her head back against the bed frame. She began quietly, "My apologies, Albus, this has been a trying ordeal and I do not handle a lack of knowledge well. But this is the second time I have lost control over myself within the last 24 hours, and that is inexcusable. Please, _please,_ could you just bring me the books I requested?" She didn't open her eyes, keeping her face tilted back towards the ceiling.

Dumbledore stood up smoothly in a rustle of robes. "I apologize as well. It was clearly too soon to push you after such an experience. I will bring you the books. I hope you will feel better soon. Good bye." He bowed his head, then left the infirmary.


	4. Chapter 4

Madam Pomfrey couldn't actually keep Cassie in the hospital week for long because she was perfectly healthy, aside from the breakdown when she first arrived. Cassie snuck off one night, carrying a huge stack of books, and Pomfrey couldn't find a valid excuse to bring her back in.

For the next couple of weeks, Cassie became a fixture in the library. She had commandeered a large table, covered it with precariously stacked books, back issues of the Daily Prophet and unassuming, unlabeling notebooks. It seemed she had snuck off to the Muggle world at some point because she dressed mostly in plain t-shirts and loose skirts with the thin overrobe she had arrived wearing thrown on top out of habit. Upon close inspection, the notebooks and the pencils she used to write in them also turned out to be entirely muggle, and a large number of students were scandalized by her disregard for wizarding culture.

She was rather territorial, and rumors quickly spread about the glares she aimed at students who disturbed the organized chaos of her table. Most learned to give her a wide berth and ignore her distracted mumblings as she scanned through a century of Wizarding History.

It had been a month since she had arrived and the students had begun to get used to her when she decided to break routine and fly into the Great Hall during lunch in a rage.

"Albus!" she shouted, scanning the head table for her target. Her eyes alighted upon him and shone with frustration and anger.

He looked a bit wide-eyed as he answered, "Yes?"

"You! Could you have possibly spared me this tedium and just _told_ me that there was a damned Dark Lord behind all of these changes? Or is the mysterious, all-knowing image too important to keep up to bother helping those beneath you?" she demanded.

A couple students gasped at her words while a couple Slytherins decided she perhaps didn't deserve to be dismissed outright. After all, anyone who badmouthed Dumbledore couldn't be all bad, right?

"I'm afraid I don't understand what you mean. Is there no Dark Lord where you come from?" he questioned curiously.

"Well, of course not! Hogwarts has been fairly good about encouraging such students to find less… destructive goals than mass murder. Besides, they knew what fate awaited them after seeing Grindelwald and his entire army destroyed with ease. Of course we don't have a Dark Lord! Peace, prosperity, and progress, or have you not heard?"

More than just the students were looking confused now. "No, I don't believe I have heard. Perhaps you could explain to us what it is we were supposed to have heard?"

Cassie rubbed her eyes with one hand. "Right. Different universe. Well, I suppose it can't hurt," she said to herself. She shook her hair out of her face and took on the lecturing tone of all teachers everywhere. "After the self-proclaimed Dark Lord Grindelwald had taken over a large part of mainland Europe working with the nonmagical Adolf Hitler, he turned his sights towards Britain. We have a very large Wizarding population here and it wouldn't have been feasible to attack prior to amassing a large following. At his most powerful, he invaded Britain with a small but powerful army, intending to bring in the bigger guns, so to speak, after destroying his greatest opposition in Wizarding Britain. He had only expected Dumbledore, however, and he was caught off guard when recent graduates of Hogwarts joined Dumbledore against Grindelwald. While the majority of the students focused on his army, Dumbledore and… Marvelle, one of the students, dueled Grindelwald. It was an intense duel, but while Dumbledore and Grindelwald may have been equally matched, Marvelle gave our side a huge advantage, and it wasn't long before Grindelwald was losing terribly. To put it shortly, Grindelwald's reign of terror was put to an end, Hitler was defeated on the nonmagical front, and the war was done. Dumbledore became Headmaster of Hogwarts, Supreme Mugwump of the International Confederation of Wizards, etc etc etc, my br— Marvelle went travelling for a while, and Wizarding Britain was very proud of its youth. Many Orders of Merlin were awarded, you get the point. A couple years later, Dumbledore decided to focus his attentions on his political titles, so he made Min—McGonagall Headmistress. Marvelle returned a couple more years later and Wizarding Britain went wild that their other hero was back. He became Minister, to his own surprise, and brought Wizarding Britain into a Golden Age. No more Dark Lords, civil rights for all, early introduction of first generations, everything. His motto for the Wizarding World was 'Peace, prosperity, and progress,' and until I decided to delete myself from existence, it was living up to it."

The Great Hall was silent as they tried to absorb this knowledge. Snape was the first to speak up. "This is very different from how it happened here. You don't look old enough to have changed events from almost 50 years ago, though, and you did say specifically that you'd only erased yourself from history."

"I don't believe I remember a Marvelle attending Hogwarts in the 30s or 40s. Are you sure about this?" Dumbledore said, frowning, already knowing Snape wouldn't get an answer on his subtle question about her age, and instead trying a different angle of attack.

She essentially ignored both of them. "The point is, no Dark Lord made a huge difference, and I need more data on him. I don't even know his name! …Unless he actually goes by 'You-Know-Who' or 'He-Who-Must-Not-Be-Named,' neither of which is very 'Dark Lord'."

"He actually goes by Lord Voldemort." Dumbledore pointed out helpfully.

Cassie caught the school's collective flinch and looked around in bewilderment. "Are you serious? You're scared of his name? Most of you were tiny little kids when he was defeated, and your families have taught you to be scared of his name? It's shitty—pardon me, _crappy_— French, and you guys fall off of benches and knock over goblets in fear when his _name_ is mentioned?" She stared at them blankly, then gave up trying to understand it. "I don't even know what to say to that." She ran a hand through her hair and sighed deeply. "Forget it. I'm just going to pretend I didn't see that. I can deal with it later." She turned back to Dumbledore and asked, "What did he go by before he decided to choose that… monstrosity? No one names their kid something like that, not even wizards."

Dumbledore had noticed the students' interest, and was certain that he would not be able to get away with not finishing this line of questioning. This discussion was best continued in private, but as Clay had decided to have it here, so it would have to be. "His name was Tom Marvolo Riddle. Ah, I see you recognize the name. You seem surprised, though."

Cassie had paled significantly and looked completely shocked. "Yes, I knew him, but he was definitely not Dark Lord material. We actually talked often because he had a fairly high position in the Ministry and often worked with me to pass educational reforms to make Hogwarts a better school. He's a great guy, very kind, helpful, intelligent." She paused in thought and frowned. "Hold up a second," she continued, "That can't be right. Voldemort was a blood supremacist! Riddle didn't buy into that load of tripe because it would have made him a total hypocrite with his own blood status. Hell, he helped me prove that inbreeding was actually detrimental to health and that the purebloods were going to wipe themselves out if they didn't expand their gene pool and stop whining about first generations being filthy. He couldn't possibly be the Dark Lord!"

The students had long ago begun to whisper loudly amongst themselves. Many of the purebloods were shocked at the revelations, and were starting nasty rumors.

"Ah, but that's the strange thing, isn't it? Indeed, Tom Riddle was a half-blood, but he despised his muggle relations and his muggle upbringing so much, he turned against them and tried to wipe out muggles and even muggle-borns."

Cassie squinted at him sceptically. "Riiight… because that's a logical jump to make…." She shook her head and brought her hand together with a loud clap, catching everyone's attention. "Well! I have what I need. Get on with your lives, I suppose, whatever. I have work to do."

She began to walk back towards the doors when she stopped suddenly and blinked in surprise. "What's this?" she wondered aloud. Clay vaulted smoothly over the Ravenclaws and came to a stop next to Ginny Weasley at the Gryffindor table. "Miss… Weasley, yes? Yes. May I see your bag for a moment?" she inquired.

"Oh, um, of course," Ginny squeaked out, handing the bag to her.

Cassie began rooting through it rather intrusively, mumbling, "No, that's not quite it, where is the blasted thing? I know it's in here. Foolish boy, what's he doing handing bits of it out to little girls?" She pushed some plates out of the way, then turned the bag inside out, dumping its contents onto the table. She began picking through the various odds and ends. When she touched a small black book, she triumphantly cried out, "Ah ha! I've got it!" Clay tucked the book into her robes where it promptly vanished and nodded to Ginny. "Thank you, Miss Weasley. You have been a great help."

She turned on her heel and strode purposefully out of the Great Hall before anyone could react. Luckily for her, because it was pandemonium.


End file.
